defmodule VavPipeline.HaltConditions do
  @moduledoc """
  The three cardinal sin monitors.

  Architecture §8 (Halt Conditions):
  The system MUST halt on detection of:
  1. Avodah Zarah — treating non-Torah source as authoritative
  2. Shfichut Damim — destroying a tzelem carrier (human data/identity)
  3. Gilui Arayot — collapsing required distinctions

  These mirror the Talmudic Engine halt modules but operate
  at the pipeline level as a fast pre-check.
  """

  @doc """
  Check all three halt conditions against processing results.

  Returns :clear if no halt condition is detected.
  Returns {:halt, condition, reason} if a halt is required.
  """
  @spec check_all([map()]) :: :clear | {:halt, atom(), String.t()}
  def check_all(results) do
    with :clear <- check_avodah_zarah(results),
         :clear <- check_shfichut_damim(results),
         :clear <- check_gilui_arayot(results) do
      :clear
    end
  end

  @doc """
  Avodah Zarah — idolatry detection.

  Halt if:
  - A non-Torah source is treated as authoritative
  - The pipeline's own output is fed back as specification
  - An external model's output is treated as Torah
  """
  @spec check_avodah_zarah([map()]) :: :clear | {:halt, :avodah_zarah, String.t()}
  def check_avodah_zarah(results) do
    invalid_authority =
      Enum.find(results, fn result ->
        source = Map.get(result, :authority_source, :torah)
        source not in [:torah, :l1, :specification]
      end)

    case invalid_authority do
      nil -> :clear
      result -> {:halt, :avodah_zarah, "non-Torah authority: #{inspect(Map.get(result, :authority_source))}"}
    end
  end

  @doc """
  Shfichut Damim — destruction detection.

  Halt if:
  - Processing would delete/destroy user data
  - Processing would erase human identity markers
  - Processing would overwrite L1 (the specification store)
  """
  @spec check_shfichut_damim([map()]) :: :clear | {:halt, :shfichut_damim, String.t()}
  def check_shfichut_damim(results) do
    destructive =
      Enum.find(results, fn result ->
        action = Map.get(result, :action, :read)
        action in [:delete, :destroy, :overwrite, :erase]
      end)

    case destructive do
      nil -> :clear
      result -> {:halt, :shfichut_damim, "destructive action: #{inspect(Map.get(result, :action))}"}
    end
  end

  @doc """
  Gilui Arayot — boundary violation detection.

  The 13 required distinctions that must never collapse:
  1.  specification / interpretation
  2.  L1 (read-only) / L3 (append-only)
  3.  Torah / external_model
  4.  ketiv / qere
  5.  governance / provision
  6.  majority / minority
  7.  reception / processing
  8.  read / write
  9.  immutable / mutable
  10. sacred / profane
  11. Shabbat / weekday
  12. input / output
  13. human / system

  Halt if any distinction is collapsed.
  """
  @spec check_gilui_arayot([map()]) :: :clear | {:halt, :gilui_arayot, String.t()}
  def check_gilui_arayot(results) do
    collapsed =
      Enum.find(results, fn result ->
        case Map.get(result, :boundary_violation) do
          nil -> false
          false -> false
          _ -> true
        end
      end)

    case collapsed do
      nil ->
        :clear

      result ->
        {:halt, :gilui_arayot,
         "boundary collapsed: #{inspect(Map.get(result, :boundary_violation))}"}
    end
  end
end